Linear compressor

ABSTRACT

Provided is a linear compressor. The linear compressor includes a stator cover coupled to the frame, a rear cover coupled to the stator cover, and springs disposed between the stator cover and the rear cover. The stator cover includes a body and a plurality of rear cover coupling parts extending from the body toward the rear cover and coupled to the rear cover, and the rear cover has a plane that is perpendicular to the axial direction so that an end of the rear cover coupling part and an end of the spring are disposed on the same plane in the axial direction. Also, other embodiments may be possible.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2018-0114161 (filed on Sep. 21, 2018), which is hereby incorporated by reference in its entirety.

BACKGROUND

The present invention relates to a linear compressor.

Generally, a compressor is a mechanical device that receives power from a power generating device Such as an electric motor or a turbine to increase pressure by compressing air, refrigerant or various other operating gases, and are used throughout the household applicance or industry.

Such compressors can be classified into reciprocating compressors, rotary compressors, and scroll compressors.

Many linear compressors are being developed which can improve the compression efficiency without mechanical loss occurring when the rotary motion. of the motor is converted into the linear motion by, particularly, connecting the piston directly to the driving motor which reciprocates lineraly and has a simple structure among the reciprocating compressor.

Generally, the linear compressor is configured to suck and compress the refrigerant while the ston is linearly reciprocated within a cylinder by a linear motor in a closed shell and then discharge the refrigerant.

A linear compressor is disclosed in Korean Patent Publication No. 10-2016-0011009 (Jan. 29, 2016) that is a prior art document.

The linear compressor that is the prior art document includes a cylinder, a frame coupled to the outside of the cylinder, a piston reciprocating in the cylinder, a stator cover coupled to the frame, a rear cover coupled to a rear end of the stator cover, and a linear motor disposed between the frame and the stator cover to provide power to the piston.

In detail, the stator cover includes a circular body and a rear cover coupling part extending from the body toward the rear cover and coupled to the rear cover.

Also, the rear cover includes a plurality of coupling flanges to be coupled to the rear cover coupling part and a plurality of spring support parts supporting an end of the spring disposed between the stator cover and the rear cover. Here, the plurality of coupling flanges and the plurality of spring support parts are alternately disposed in a circumferential direction of the rear cover.

Also, a plate spring that is closely attached to an inner circumferential surface of a shell may be fixed to a rear surface of the rear cover so that internal components of the compressor are supported by the shell.

However, the linear compressor according to the related art may have following limitations.

First, according to the related art, since an end of the rear cover coupling part extending from the rear surface of the stator cover and an end of a resonant spring are not supported on the same plane, the rear cover may have a complicated shape.

That is, since the spring support part on which the resonant spring is supported and the coupling flange coupled to the rear cover coupling part have to be disposed on planes different from each other, the shape of the rear cover may be complicated, and thus, the rear cover is weakened in strength.

Second, since a separate coupling member for fixing a support device that is elastically supported on the shell is required for the rear cover according to the related art, an additional process for coupling the support device to the rear cover is required. As a result, the product unit price and the assembling time may increase.

SUMMARY

Embodiments provide a linear compressor in which an end of a stator cover and an end of a resonant spring are supported together on the same plane that is perpendicular to an axial direction of the rear cover.

Embodiments also provide a linear compressor in which a rear cover is simplified in shape to improve strength of the rear cover.

Embodiments also provide a linear compressor in which a rear cover is minimized in thickness in an axial direction to reduce a size of a shell, thereby miniaturize the linear compressor.

Embodiments also provide a linear compressor in which a stator cover, a rear cover, and a plate spring are coupled to each other at one time.

Embodiments also provide a linear compressor in which a resonant spring disposed between a stator cover and a rear cover withstands a larger load or a repeated load.

In one embodiment, a linear compressor includes: a shell; a cylinder provided in the shell to define a compression space for a refrigerant; a frame coupled to the outside of the cylinder; a piston configured to reciprocate in an axial direction within the cylinder; a stator cover coupled to the frame; a rear cover coupled to the stator cover; and springs disposed between the stator cover and the rear cover.

Here, the stator cover may include a body and a plurality of rear cover coupling parts extending from the body toward the rear cover and coupled to the rear cover, and the rear cover may have a plane that is perpendicular to the axial direction so that an end of the rear cover coupling part and an end of the spring are disposed on the same plane in the axial direction.

Thus, since a structure in which an end of the stator cover and an end of the resonant spring are supported together on the same plane is provided, the rear cover may be simplified in shape to improve strength of the rear cover. In addition, since the rear cover has a single disk shape, the shell may be reduced in size to miniaturize the linear compressor.

An opening through which the piston passes may be defined in the body of the stator cover, and the plurality of rear cover coupling parts may be disposed to be spaced apart from each other in a circumferential direction of the body.

Also, a plurality of coupling holes to be respectively coupled to the plurality of rear cover coupling parts may be defined in the rear cover, and the plurality of coupling holes may be disposed to be spaced apart from each other in a circumferential direction of the rear cover.

Also, a plurality of spring coupling protrusions coupled to one or more of the plurality of springs may be further disposed on the rear cover, and the plurality of spring coupling protrusions may be disposed to be spaced apart from each other in a circumferential direction of the rear cover.

Here, the plurality of coupling holes and the plurality of spring coupling protrusions may be alternately disposed in the circumferential direction of the rear cover.

Also, the rear cover may include a first surface configured to support at least one or more of the plurality of springs and a second surface corresponding to an opposite side of the first surface, and a support device configured to support the rear cover on the shell is installed on the second surface.

The support device may include: a spring support part inserted into the second surface of the rear cover; and a plate spring inserted into the spring support part, and the plate spring may include: a spring body inserted into the spring support part; and a plurality of spring coupling parts extending from a circumference of the spring body to points reaching the plurality of coupling holes.

Here, a spring coupling hole may be defined at a point facing each of the plurality of coupling holes in each of the plurality of spring coupling parts, and thus, the coupling member may be coupled to the rear cover coupling part by continuously passing through the spring coupling hole and the coupling hole.

Thus, the stator cover, the rear cover, and the plate spring may be coupled to each other at one time to simplify a structure of the rear cover and significantly reduce an assembling time. That is, a coupling member for separately fixing the plate spring to a rear surface of the rear cover may not be required.

In another embodiment, the plurality of rear cover coupling parts may be disposed to be spaced apart from each other along a circumference of the opening in a circumferential direction, and the springs may be disposed to surround the outsides of the plurality of rear cover coupling parts.

For example, each of the springs may include a plurality of spring strands, wherein each of the spring strands may include: a spring body extending in a spiral direction with respect to a spring central axis (C) extending in an axial direction; a front spring link extending from one side of the spring body to define one end of the spring body; and a rear spring link extending from the other side of the spring body to define the other end of the spring body.

Here, the front spring link of each of the plurality of spring strands may be fixed to the support, and the rear spring link of each of the plurality of spring strands may be fixed to the rear cover. Thus, since both ends of the spring may be fixed to utilize all the tensile force and the compression force of the spring, the spring may support a larger or repeated load.

The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a linear compressor according to a first embodiment.

FIG. 2 is an exploded perspective view of a main body of a compressor, which is accommodated in a shell of the compressor according to the first embodiment.

FIG. 3 is a longitudinal cross-sectional view of the compressor according to the first embodiment.

FIG. 4 is a front perspective view illustrating a portion of the main body of the compressor according to the first embodiment.

FIG. 5 is a rear perspective view of FIG. 4.

FIG. 6 is an exploded perspective view of FIG. 5.

FIG. 7 is a cross-sectional view taken along line II-II′ of FIG. 4.

FIG. 8 is a front perspective view of a stator cover according to the first embodiment.

FIG. 9 is a rear perspective view of the stator cover.

FIG. 10 is a front perspective view of the stator cover.

FIG. 11 is a rear perspective view illustrating a portion of a main body of a compressor according to a second embodiment.

FIG. 12 is an exploded perspective view of FIG. 11.

FIG. 13 is a cross-sectional view taken along line of FIG. 11.

FIG. 14 is a rear perspective view illustrating a portion of a main body of a compressor according to a third embodiment.

FIG. 15 is a rear perspective view of a stator cover according to the third embodiment.

FIG. 16 is a perspective view of a resonant spring according to the third embodiment.

FIG. 17 is a perspective view of the resonant spring of FIG. 16 when viewed in a different direction.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings.

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense.

Also, in the description of embodiments, terms such as first, second, A, B, (a), (b) or the like may be used herein when describing components of the present invention. Each of these terminologies is not used to define an essence, order or sequence of a corresponding component but used merely to distinguish the corresponding component from other component(s). It should be noted that if it is described in the specification that one component is “connected,” “coupled” or “joined” to another component, the former may be directly “connected,” “coupled,” and “joined” to the latter or “connected”, “coupled”, and “joined” to the latter via another component.

Hereinafter, a linear compressor according to a first embodiment will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view of a linear compressor according to a first embodiment.

Referring to FIG. 1, a linear compressor 10 according to an embodiment may include a shell 101 having a cylindrical shape and a pair of shell covers coupled to both ends of the shell 101. The pair of shell covers may include a first shell cover 102 (see FIG. 3) of a refrigerant suction-side and a second shell cover 103 of a refrigerant discharge-side.

In detail, a leg 50 may be coupled to a lower portion of the shell 101. The leg 50 may be coupled to a base of a product in which the linear compressor 10 is installed. For example, the product may include a refrigerator, and the base may include a machine room base of the refrigerator. For another example, the product may include an outdoor unit of an air conditioner, and the base may include a base of the outdoor unit.

The shell 101 may have a lain cylindrical shape. When the linear compressor 10 is installed on the machine room base of the refrigerator, a machine room may be reduced in height. That is to say, a central axis in a longitudinal direction of the shell 101 may correspond to a central axis of the main body of the compressor, which will be described later. The central axis of the main body of the compressor may correspond to a central axis of each of the cylinder and the piston, which constitute the main body of the compressor.

A terminal block 108 may be installed on an outer surface of the shell 101. The terminal block 108 may be understood as a connection part for transferring external power to a motor assembly (see reference numeral 140 of FIG. 3) of the linear compressor 10.

A bracket 109 is installed outside the terminal block 108. The bracket 109 may protect the terminal block 108 against an external impact and the like.

Both ends of the shell 101 may be opened. The first and second shells 102 and 103 may be coupled to both the opened ends of the shell 101. An inner space of the shell 101 may be sealed by the shell covers 102 and 103.

In FIG. 1, the first shell cover 102 may be disposed at a right portion (or a rear end) of the linear compressor 10, and the second shell cover 103 may be disposed at a left portion (or a front end) of the linear compressor 10. Also, the end of the shell 101 on which the first shell cover 102 is mounted may be defined as a suction-side end, and the end of the shell 101 on which the second shell cover 103 is mounted may be defined as a discharge-side end.

The linear compressor 10 may further include a plurality of pipes 104, 105, and 106 provided in the shell 101 or the shell covers 102 and 103. A refrigerant may be introduced into the shell 101 through the plurality of pipes 104, 105, and 106 and then compressed to be discharged to the outside of the shell 101.

In detail, the plurality of pipes 104, 105, and 106 may include a suction pipe 104 through which the refrigerant is suctioned into the linear compressor 10, a discharge pipe 105 through which the compressed refrigerant is discharged from the linear compressor 10, and a process pipe through which the refrigerant is supplemented to the linear compressor 10.

For example, the suction pipe 104 may be coupled to the first shell cover 102, and the refrigerant may be suctioned into the linear compressor 10 through the suction pipe 104 in an axial direction.

The discharge pipe 105 may be coupled to an outer circumferential surface of the shell 101. The refrigerant suctioned through the suction pipe 104 may flow in the axial direction and then be compressed. Also, the compressed refrigerant may be discharged through the discharge pipe 105 to the outside. The discharge pipe 105 may be disposed at a position that is adjacent to the second shell cover 103 rather than the first shell cover 102.

The process pipe 106 may be coupled to an outer circumferential surface of the shell 101. A worker may inject the refrigerant into the linear compressor 10 through the process pipe 106.

The process pipe 106 may be coupled to the shell 101 at a height different from that of the discharge pipe 105 to avoid interference with the discharge pipe 105. The height may be defined as a distance from the leg 50 to each of the discharge pipe 105 and the process pipe 106 in a vertical direction (or a radial direction of the shell). Also, since the discharge pipe 105 and the process pipe 106 are coupled to the outer circumferential surface of the shell 101 at the heights different from each other, work convenience for injecting the refrigerant may be improved.

A cover support part 102 a (see FIG. 3) may be disposed at a center of an inner surface of the first shell cover 102. A second support device 185 that will be described later may be coupled to the cover support part 102 a. The cover support part 102 a and the second support device 185 may be understood as devices for supporting a rear end of the main body of the compressor to maintain a state in which the main body of the compressor is horizontal in the shell 101. Here, the main body of the compressor represents a component set provided in the shell 101. For example, the main body may include a driving part that reciprocates forward and backward and a support part supporting the driving part.

As illustrated in FIG. 3, the driving part may include components such as the piston 130, a magnet frame 138, a permanent magnet 146, a support 137, and a suction muffler 150. Also, the support part may include components such as springs 176 a and 176 b, a rear cover 170, a stator cover 200, a first support device 184, and a second support device 185.

A stopper 102 b (see FIG. 3) may be disposed on an edge of the inner surface of the first shell cover 102. The stopper 102 b may be understood as a component for preventing the main body of the compressor, particularly, the motor assembly 140 from being bumped by the shell 101 and thus damaged due to the shaking, the vibration, or the impact occurring during the transportation of the linear compressor 10. The stopper 102 b may be disposed adjacent to the rear cover 170 that will be described later. Thus, when the linear compressor 10 is shaken, the rear cover 170 may interfere with the stopper 102 b to prevent the impact from being directly transmitted to the motor assembly 140.

FIG. 2 is an exploded perspective view of the main body of the compressor, which is accommodated in the shell of the compressor according to the first embodiment, and FIG. 3 is a longitudinal cross-sectional view of the compressor according to the first embodiment.

Referring to FIGS. 2 and 3, the main body of the linear compressor 10, which is provided in the shell 101, according to an embodiment may include a frame 110, a cylinder 120 inserted into a center of the frame 110, a piston 130 that linearly reciprocates within the cylinder 120, and the motor assembly 140 that gives driving force to the piston 130. The motor assembly 140 may be a linear motor that allows the piston 130 to linearly reciprocate in the axial direction of the shell 101.

In detail, the linear compressor 10 may further include the suction muffler 150. The suction muffler 150 may be coupled to the piston 130 to reduce noise generated from the refrigerant suctioned through the suction pipe 104. Also, the refrigerant suctioned through the suction pipe 104 flows into the piston 130 via the suction muffler 150. For example, while the refrigerant passes through the suction muffler 150, the flow noise of the refrigerant may be reduced.

The suction muffler 150 may include a plurality of mufflers. The plurality of mufflers may include a first muffler 151, a second muffler 152, and a third muffler 153, which are coupled to each other.

The first muffler 151 is disposed within the piston 130, and the second muffler 152 is coupled to a rear end of the first muffler 151. Also, the third muffler 153 accommodates the second muffler 152 therein, and a front end of the third muffler 153 may be coupled to the rear end of the first muffler 151.

In view of a flow direction of the refrigerant, the refrigerant suctioned through the suction pipe 104 may successively pass through the third muffler 153, the second muffler 152, and the first muffler 151. In this process, the flow noise of the refrigerant may be reduced.

A muffler filter 154 may be mounted on the suction muffler 150. The muffler filter 154 may be disposed on an interface on which the first muffler 151 and the second muffler 152 are coupled to each other. For example, the muffler filter 154 may have a circular shape, and an edge of the muffler filter 154 may be disposed and supported between coupling surfaces of the first and second mufflers 151 and 152.

Here, the “axial direction” may be understood as a direction corresponding to the reciprocating direction of the piston 130, i.e., an extension direction of the longitudinal central axis of the cylindrical shell 101. Also, in the “axial direction”, a direction from the suction pipe 104 toward a compression space P, i.e., a direction in which the refrigerant flows may be defined as a “frontward direction”, and a direction opposite to the frontward direction may be defined as a “rearward direction”. When the piston 130 moves forward, the compression space P may be compressed.

On the other hand, the “radial direction” may be defined as a radial direction of the shell 101, i.e., a direction perpendicular to the reciprocating direction of the piston 130.

The piston 130 may include a piston body 131 having an approximately cylindrical shape and a piston flange part 132 extending from a rear end of the piston body 131 in the radial direction. The piston body 131 may reciprocate inside the cylinder 120, and the piston flange part 132 may reciprocate outside the cylinder 120. The piston body 131 is configured to accommodate at least a portion of the first muffler 151.

The cylinder 120 has a compression space P in which the refrigerant is compressed by the piston 130. Also, a plurality of suction holes 133 are defined in a potion that is spaced a predetermined distance from a center of a front surface of the piston body 131 in the radial direction.

In detail, the plurality of suction holes 133 may be arranged to be spaced apart from each other in a circumferential direction of the piston 130, and the refrigerant may be introduced into the compression space P through the plurality of suction holes 133. The plurality of suction holes 133 may be disposed to be spaced a predetermined distance from each other in the circumferential direction of the front surface of the piston 130 or may be provided in a plurality of groups.

Also, a suction valve 135 that selectively opens the suction hole 133 is provided at the front of the suction hole 133. Also, the suction valve 135 is fixed to a front surface of the piston body 131 by a coupling member 135a such as a screw or a bolt.

A discharge cover unit 190 providing a discharging space for the refrigerator discharged into the compressor space P and a discharge valve assembly coupled to the inside of the discharge cover unit 190 to discharge the refrigerant compressed in the compression space P to the discharge space are provided at the front of the compression space P.

The discharge cover unit 190 may be provided in a shape in which a plurality of covers are laminated. Also, a coupling hole or coupling groove (not shown) to which the first support device 184 is coupled may be defined in the discharge cover coupled to the outermost side (or the frontmost side) of the plurality of covers.

In detail, the discharge cover unit 190 includes a cover housing 191 fixed to the front surface of the frame 110 and a discharge cover 192 disposed inside the cover housing 191. Also, the discharge cover unit 190 may further include a cylindrical fixing ring 220 that is closely attached to an inner circumferential surface of the discharge cover 192. The fixing ring 220 may be made of a material having a thermal expansion coefficient different from that of the discharge cover 192 to prevent the discharge cover 192 from being separated from the cover housing 191.

Also, the discharge valve assembly may include a discharge valve 161 and a spring assembly 240 providing elastic force in a direction in which the discharge valve 161 is closely attached to the front end of the cylinder 120.

In detail, the discharge valve 161 may be separated from the front surface of the cylinder when a pressure in the compression space P is greater than a discharge pressure to discharge the compressed refrigerant into the discharge space (or a discharge chamber) defined in the discharge cover 192.

The spring assembly 240 may include a valve spring 242 having a plate spring shape, a spring support part 241 surrounded on an edge of the valve spring 242 to support the valve spring 242, and a friction ring 243 inserted into an outer circumferential surface of the spring support part 241.

Also, when the pressure in the compression space P is greater than the discharge pressure, the valve spring 242 may be elastically deformed toward the discharge cover 192, and thus, the discharge valve 161 may be spaced apart from the front end of the cylinder 120.

A central portion of a front surface of the discharge valve 161 is fixed and coupled to a center of the valve spring 242, and a rear surface of the discharge valve 161 is closely attached to the front surface (or the front end) of the cylinder 120 by the elastic force of the valve spring 242.

When the discharge valve 161 is supported on the front surface of the cylinder 120, the compression space may be maintained in the sealed state. When the discharge valve 161 is spaced apart from the front surface of the cylinder 120, the compression space P may be opened to allow the refrigerant in the compression space P to be discharged.

The compression space P may be understood as a space defined between the suction valve 135 and the discharge valve 161. Also, the suction valve 135 may be disposed on one side of the compression space P, and the discharge valve 161 may be disposed on the other side of the compression space P, i.e., an opposite side of the suction valve 135.

While the piston 130 linearly reciprocates within the cylinder 120, when the pressure of the compression space P is less than a suction pressure of the refrigerant, the suction valve 135 may be opened to suction the refrigerant into the compression space P.

On the other hand, when the pressure in the compression space P is greater than the suction pressure of the refrigerant, the suction valve 135 is closed, and the piston moves forward to compress the refrigerant within the compression space P.

When the pressure in the compression space P is greater than the pressure (the discharge pressure) in the discharge space, the valve spring 242 is deformed forward to separate the discharge valve from the cylinder 120. Also, the refrigerant within the compression space P is discharged into the discharge space defined in the discharge cover 192 through a gap between the discharge valve 161 and the cylinder 120.

When the refrigerant is completely discharged, the valve spring 242 may provide restoring force to the discharge valve 161 so that the discharge valve 161 is closely attached again to the front end of the cylinder 120.

Also, a gasket 210 may be provided on the front surface of the spring support part 241. When the discharge valve 161 is opened, the spring assembly 240 may move in the axial direction to be directly bumped to the discharge cover 192, thereby reducing noise from occurring.

The linear compressor 10 may further include a cover pipe 162. The cover pipe 162 is coupled to the cover housing 191 to discharge the refrigerant, which is discharged from the compression space P to the discharge space within the discharge cover unit 190, to the outside. For this, the cover pipe 162 has one end coupled to the cover housing 191 and the other end coupled to the discharge pipe 105 provided in the shell 101.

The cover pipe 162 may be made of a flexible material and roundly extend along the inner circumferential surface of the shell 101.

The frame 110 may be understood as a component for fixing the cylinder 120. For example, the cylinder 120 may be inserted in the axial direction of the shell 101 at the central portion of the frame 110. Also, the discharge cover unit 190 may be coupled to the front surface of the frame 110 by a coupling member.

Also, an insulation gasket 230 may be disposed between the cover housing 191 and the frame 110. In detail, the insulation gasket 230 may be disposed on the front surface of the frame 110 contacting the rear surface or the rear end of the cover housing 191 to prevent heat of the discharge cover unit 190 from being transferred to the frame 110.

The motor assembly 140 may include an outer stator 141 fixed to the frame 110 to surround the cylinder 120, an inner stator 148 disposed to be spaced inward from the outer stator 141, and a permanent magnet 146 disposed in a space between the outer stator 141 and the inner stator 148.

The permanent magnet 146 may linearly reciprocate in the axial direction by mutual electromagnetic force generated between the outer stator 141 and the inner stator 148. Also, the permanent magnet 146 may be provided as a single magnet having one polarity or be provided by coupling a plurality of magnets having three polarities to each other.

The magnet frame 138 may have a cylindrical shape of which a front surface is opened, and a rear surface is closed. Also, the permanent magnet 146 may be coupled to an end of the opened front surface of the magnet frame 138 or an outer circumferential surface of the magnet frame 138. Also, a through-hole through which the suction muffler 150 passes may be defined in a center of the rear surface of the magnet frame 138, and the suction muffler 150 may be fixed to the rear surface of the magnet frame 138.

In detail, the piston flange part 132 extending from a rear end of the piston 130 in the radial direction is fixed to the rear surface of the magnet frame 138. Also, an edge of the rear end of the first muffler 151 is disposed between the piston flange part 132 and the rear surface of the magnet frame 138 so as to be fixed to the center of the rear surface of the magnet frame 138.

Also, when the permanent magnet 146 reciprocates in the axial direction, the piston 130 may reciprocate together with the permanent magnet 146 in the axial direction.

The outer stator 141 may include a coil winding body and a stator core 141 a. The coil winding body may include a bobbin 141 b, a coil 141 c wound in a circumferential direction of the bobbin 141 b, and a terminal part 141 d guiding a power line connected to the coil 141 c so that the power line is withdrawn or exposed to the outside of the outer stator 141.

The stator core 141 a may include a plurality of core blocks in which a plurality of lamination plates, each of which has a ‘⊏’ shape, are laminated in the circumferential direction. The plurality of core blocks may be disposed to surround at least a portion of the coil winding body.

A stator cover 200 may be disposed on one side of the outer stator 141. In detail, a front end of the outer stator 141 is fixed and supported on the frame 110, and the stator cover 200 is fixed to a rear end of the outer stator 141.

Also, a cover coupling member 149 a having a rod shape passes through the stator cover 200 and then is inserted into and fixed to the frame 110 via an edge of the outer stator 141. That is, the motor assembly 140 may be stably fixed to the rear surface of the frame 110 by the cover coupling member 149 a.

The inner stator 148 is fixed to an outer circumference of the frame 110. Also, in the inner stator 148, the plurality of lamination plates are laminated outside the frame 110 in the circumferential direction.

In detail, the frame 110 may include a frame head ll0 a having a disk shape and a frame body 110 b extending from a center of a rear surface of the frame head 110 a and accommodating the cylinder 120 therein. Also, the discharge cover unit 190 is fixed to a front surface of the frame head 110 a, and the inner stator 148 is fixed to an outer circumferential surface of the frame body 110 b. Also, the plurality of lamination plates constituting the inner stator 148 are laminated in the outer circumferential surface of the frame body 110 b.

The linear compressor 10 may further include a support 137 supporting the rear end of the piston 130. The support 137 may be coupled to a rear portion of the piston 130 and have a hollow part so that the suction muffler 150 passes through the inside of the support 137.

The support 137 is fixed to the rear surface of the magnet frame 138. Also, the piston flange part 132, the magnet frame 138, and the support 137 are coupled to each other by the coupling member to form one body.

A balance weight 179 may be coupled to the support 137. A weight of the balance weight 179 may be determined based on a driving frequency range of the main body of the compressor.

The linear compressor 10 may further include the rear cover 170. A front end of the rear cover 170 is fixed to the stator cover 200 to extend backward and then is supported by a second support device 185.

Detailed configurations of the stator cover 200 and the rear cover 170 will be described later.

The linear compressor 10 may further include an inflow guide part (not shown) that is coupled to the rear cover 170 to guide an inflow of the refrigerant into the suction muffler 150. A front end of the inflow guide part may be inserted into the suction muffler 150.

The linear compressor 10 may include a plurality of resonant springs that are adjusted in natural frequency to allow the piston 130 to perform a resonant motion.

In detail, the plurality of resonant springs may include a plurality of first springs 176 a disposed between the support 137 and the stator cover 200 and a plurality of second springs 176 b disposed between the support 137 and the rear cover 170.

The piston 130 may stably linearly reciprocate within the shell 101 of the linear compressor 10 due to operations of the plurality of springs and also minimize an occurrence of vibration or noise due to the movement of the piston 130.

The support 137 may include a spring insertion member 137 a into which a rear end of each of the first springs 176 a is inserted.

The linear compressor 10 may include the frame 110 and a plurality of sealing members for increasing coupling force between components around the frame 110.

In detail, the plurality of sealing members may include a first sealing member 129 a disposed between the cylinder 120 and the frame 110 and a second sealing member 129 b disposed at a portion at which the frame 110 and the inner stator 148 are coupled to each other.

Each of the first and second sealing members 129 a and 129 b may have a ring shape.

The linear compressor 10 may further include a pair of first support devices 184 supporting the front end of the main body of the compressor 10. In detail, each of the pair of first support devices 184 has one end fixed to the discharge cover unit 190 and the other end that is closely attached to the inner circumferential surface of the shell 101. Also, the pair of second support devices 185 are spread at a range of angle of about 90 degrees to about 120 degrees to support the discharge cover unit 190.

Also, the cover housing 191 constituting the discharge cover unit 190 may include a flange part 191 f that is closely attached to a front surface of the frame head 110 a, a chamber part 191 e provided in the axial direction of the shell 101 at an inner edge of the flange part 191 f, a support device fixing part 191 d further extending from a front surface of the chamber part 191 e, and a partition sleeve 191 a extending from the inside of the chamber part 191 e.

Also, an end of each of the pair of first support devices 184 is fixed to an outer circumferential surface of the support device fixing part 191 d.

The linear compressor 10 may further include a second support device 185 supporting the rear end of the main body of the compressor 10. The second support device 185 may include a second support spring 186 having a circular plate shape and a second spring support part 187 inserted into a central portion of the second support spring 186.

Also, an outer edge of the second support spring 186 is fixed to the rear surface of the rear cover 170 by the coupling member, and the second spring support part 187 is coupled to the cover support part 102 a provided at a center of the first shell cover 102 so that the rear end of the main body of the compressor is elastically supported at the central portion of the first shell cover 102.

The refrigerant discharged from the compression space P by opening the discharge valve 161 passes through slits provided in the valve spring 241 and then is guided to a discharge chamber D provided in the chamber part 191 e. Also, the refrigerant guided into the discharge chamber D is discharged to the outside of the compressor through the cover pipe 162.

FIG. 4 is a front perspective view illustrating a portion of the main body of the compressor according to the first embodiment, FIG. 5 is a rear perspective view of FIG. 4, FIG. 6 is an exploded perspective view of FIG. 5, FIG. 7 is a cross-sectional view taken along line II-II′ of FIG. 4, FIG. 8 is a front perspective view of the stator cover according to the first embodiment, FIG. 9 is a rear perspective view of the stator cover, and FIG. 10 is a front perspective view of the stator cover.

Referring to FIGS. 4 to 10, the rear cover 170 is coupled to a rear end of the stator cover 200, and the piston 130, the magnet frame 138, the support 137, and the springs 176 a and 176 b are disposed in a space between the rear cover 170 and the stator cover 200.

In detail, the stator cover 200 may include a body 210 having an opening 211 through which the piston 130 passes and one or more rear cover coupling part 220 extending from the body 210 toward the rear cover 170.

The body 210 include a front surface 210 a coupled to the frame 110 and a rear surface 210 b supporting the first spring 176 a. The front surface 210 a and the rear surface 210 b may form a plane. That is, the body 210 may have a plane that is perpendicular to the axial direction.

For example, the body 210 may have a disk shape. Also, the opening 211 may be defined in a central portion of the body 210, and the piston 130 and the magnet 138 may pass through the opening 211.

Also, the body 210 includes a coupling hole 212 through which a coupling member (not shown) passes.

The coupling hole 212 extends from the front surface 210 a to the rear surface 210 b of the body 210. Also, the coupling hole 212 may be provided in plurality. The plurality of coupling holes 212 may be disposed to be spaced apart from each other in the front surface 210 a in the circumferential direction. Thus, the plurality of coupling members may pass through the plurality of coupling holes 212 so as to be coupled to the frame 110.

Also, the body 210 may further include a plurality of spring coupling protrudes respectively coupled to the first springs 176 a.

The plurality of spring coupling protrusions 213 extend backward from the rear surface 210 b of the body 210. Here, the first springs 176 a are seated on the rear surface 210 b of the body 210. When the plurality of first springs 176 a are seated on the rear surface 210 b of the body 210, each of the spring coupling protrusions 213 is inserted into each of the first springs 176 a. The plurality of spring coupling protrusions 213 may be disposed between rear cover coupling parts 220 that will be described later.

Thus, an end of the first spring 176 contacting the body 210 may be prevented from being slid by each of the spring coupling protrusions 213. The plurality of first springs 176 a may be disposed to be spaced apart from each other in a circumferential direction of the body 210.

Each of the rear cover coupling parts 220 lengthily extends backward from the rear surface 210 b of the body 210 so as to be coupled to the rear cover 170. Here, the rear cover coupling part 220 may have a cross-sectional area that gradually decreases backward from the rear surface 210 b of the body 210. That is, a front surface of the rear cover coupling part 220 may have an area less than that of the rear surface 210.

The plurality of rear cover coupling parts 220 may be disposed to be spaced apart from each other in the circumferential direction of the body 210. Here, for example, the plurality of rear cover coupling parts 220 may be provided in three. The three rear cover coupling parts 220 may be disposed to be spaced the same interval from each other in the circumferential direction. That is, the three rear cover coupling parts 220 may be spaced an angle of about 120 degrees from each other with respect to a central axis of the body 210.

Also, a coupling groove 221 to which a first coupling member S1 is coupled may be defined in each of the rear cover coupling parts 220.

The coupling groove 221 may be defined in a rear surface 220 b corresponding to an end of the rear cover coupling part 220. That is, the coupling groove 221 may be recessed by a predetermined depth forward from the rear surface 220 b of the rear cover coupling part 220. Thus, the first coupling member S1 may be coupled to the coupling groove 221 after passing through the rear cover 170.

Also, a plurality of guide grooves 222 into which guide pins (not shown) that will be described later are inserted may be defined in the rear cover coupling part 220. The plurality of guide grooves 222 may be defined in both sides of the coupling groove 221.

The rear cover 170 has a disk shape and is coupled to the end of the stator cover 200. The rear cover 170 is disposed at a rear side of the stator cover 200.

In detail, the rear cover 170 includes a front surface 170 a supporting the second spring 176 b and a rear surface 170 b supporting the second support spring 186.

The front surface 170 a and/or the rear surface 170 b of the rear cover 170 may be provided as a flat surface. Also, the rear cover 170 may have an outer diameter less than that of the stator cover 200. The front surface of the rear cover 170 may be disposed to face the rear surface 210 b of the stator cover 200. That is, central axes of the rear cover 170 and the stator cover 200 may match each other.

The rear cover 170 may further include a plurality of spring coupling protrusions 171 coupled to the second springs 176 b.

The plurality of spring coupling protrusions 171 extend forward from the front surface 170 a of the rear cover 170. Here, the second springs are seated on the front surface 170 a of the rear cover 170. When the plurality of second springs 176 b are seated on the front surface 170 a of the rear cover 170, each of the spring coupling protrusions 171 is inserted into each of the second springs 176 b.

Thus, an end of the second spring 176 b contacting the rear cover 170 may be prevented from being slid by each of the spring coupling protrusions 171. The plurality of second springs 176 b may be disposed to be spaced apart from each other in a circumferential direction of the rear cover 170.

Also, the rear cover 170 further includes a coupling hole 172 that is coupled to the rear cover coupling part 220 by using the first coupling member S1.

The coupling hole 172 is disposed at a position corresponding to the coupling groove 221 of the rear cover coupling part 220. The coupling hole 172 may pass through from the rear surface 170 b up to the front surface 170 a of the rear cover 170. Also, the coupling hole 172 may be provided in plurality, and the plurality of coupling holes 172 may be disposed to be spaced apart from each other in the circumferential direction. Thus, the plurality of first coupling members S1 may pass through the coupling hole 172 and then be respectively coupled to the rear cover coupling parts 220.

Here, a spacer 181 may be disposed between the plurality of rear cover coupling parts 220 the front surface 170 a of the rear cover 170. A distance from the stator cover 200 to a rear end of the rear cover 170 may be determined by adjusting a thickness of the spacer 181.

Also, when the rear cover 170 and the stator cover 200 are assembled with each other, a coupling hole 172 and a plurality of guide holes 173 into which a guide pin is inserted to align the coupling groove 221 may be defined in the rear cover 170.

The plurality of guide holes 173 may be spaced apart from each other in the circumferential direction of the rear cover 170. For example, the coupling groove 221 may be disposed between the plurality of guide grooves 222, and the coupling hole 172 may be disposed between the plurality of guide holes 173.

In this embodiment, a length Ll of the rear cover coupling part 220 in the axial direction may be equal to a distance from the front end of the first spring 176 a up to a rear end of the second spring 176 b.

That is, the front surface 170 a of the rear cover 170, which contacts the rear cover coupling part 220, and the front surface 170 a of the rear cover 170, which contacts the rear end of the second spring 170 b may be disposed on the same plane P in the axial direction.

Thus, since the end of the stator cover 200 and the end of the resonant spring 176 b are supported on the same plane P that is perpendicular to the axial direction of the rear cover 170, the rear cover 170 may be simplified in shape. That is, the rear cover 170 may be easily manufactured in the disk shape. The stator cover 200 may be manufactured through aluminum casting. Thus, when the rear cover 170 is simplified in shape, the shell may be reduced in size, and thus, the linear compressor may be miniaturized.

Also, the second support device 185 is coupled to the rear cover 170.

The second support device 185 may include a second support spring 186 having a circular plate shape and a second spring support part 187 inserted into a central portion of the second support spring 186.

An outer edge of the second support spring 186 is fixed to the rear surface 170 b of the rear cover 170 by a second coupling member S2. Also, the second spring support part 187 is mounted on a central portion of the rear surface 170 b of the rear cover 170 and coupled to the cover support part 102 a disposed at a center of the first shell cover 102. Thus, the rear end of the main body of the compressor may be elastically supported at the central portion of the first shell cover 102.

The support 137 may be coupled to the rear portion of the piston 130 and have the hollow part so that the suction muffler 150 passes through the inside of the support 137. Also, the support 137 may be fixed to a rear surface of the magnet frame 138.

The support 137 may support the end of each of the first spring 176 a and the second spring 186 b. The first spring 176 a is elastically installed between the body 210 of the stator cover 200 and the support 137, and the second spring 176 b is elastically installed between the support 137 and the rear cover 170.

The first spring 176 a may be provided in plurality, and the plurality of first springs 176 a may be disposed to be spaced apart from each other in the circumferential direction of the body 100 of the stator cover 200. The second spring 176 b may be provided in plurality, and the plurality of second springs 176 b may be disposed to be spaced apart from each other in the circumferential direction of the rear cover 170. The first and second springs 176 a and 176 b may be disposed to at least partially overlap each other in the axial direction.

FIG. 11 is a rear perspective view illustrating a portion of a main body of a compressor according to a second embodiment, FIG. 12 is an exploded perspective view of FIG. 11, and FIG. 13 is a cross-sectional view taken along line III-III′ of FIG. 11.

This embodiment is the same as the first embodiment except for a structure of a second support device. Thus, only characterized parts of the current embodiment will be principally described below, and descriptions of the same part as that of the first embodiment will be quoted from the first embodiment.

Referring to FIGS. 11 to 13, a rear cover 170 is coupled to a rear end of a stator cover 200, and a piston 130, a magnet frame 138, a support 137, and springs 176 a and 176 b are disposed in a space between the rear cover 170 and the stator cover 200.

The stator cover 200, the rear cover 170, the piston 130, the magnet frame 138, the support 137, and the springs 176 a and 176 b are the same as those according to the foregoing first embodiment, and thus, their detailed descriptions will be omitted.

This embodiment has a feature in which a rear cover coupling part 220 of the stator cover 200 and a second support spring 186 of a second support device 185 are coupled together by a first coupling member S1 for coupling the rear cover 170.

In detail, the rear cover 170 includes a coupling hole 172 that is coupled to the rear cover coupling part 220 by using the first coupling member Sl.

The coupling hole 172 is disposed at a position corresponding to a coupling groove 221 of the rear cover coupling part 220. The coupling hole 172 may pass through from a rear surface 170 b up to a front surface 170 a of the rear cover 170. Also, the coupling hole 172 may be provided in plurality, and the plurality of coupling holes 172 may be disposed to be spaced apart from each other in a circumferential direction. Thus, the plurality of first coupling members S1 may be coupled to the rear cover coupling part 220 by passing through the coupling hole 172.

Here, a second support spring 186 may be disposed on the rear surface 170 b of the rear cover 170 so that the second support sing 186 and the rear cover 170 are coupled together by the first coupling member S1.

That is, the second support spring 186 according to this embodiment includes a spring body 186 a inserted into a second spring support part 187 mounted on the rear cover 170 and a spring coupling part 186 b extending outward in a radial direction of the spring body 186 a.

The spring body 186 a has a circular plate spring shape and is inserted into the second spring support part 187. Also, a spring coupling part 186 b extending outward in the radial direction is disposed on an outer circumferential surface of the spring body 186 a.

At least one or more spring coupling parts 186 b may be disposed on a circumference of the spring body 186 a. Here, the plurality of spring coupling parts 186 b may extend up to a distance corresponding from an outer circumferential surface of the spring body 186 a to the coupling hole 172 of the rear cover 170. Also, a spring coupling hole 186 c is defined in the spring coupling part 186 b at a portion corresponding to the coupling hole 172. That is, the coupling hole 172 and the spring coupling hole 186 c are disposed to be spaced apart from each other to face each other.

Thus, the second support spring 186, the rear cover 170, and the rear cover coupling part 220 may be coupled to each other at one time by the single first coupling member S1.

Also, a sleeve 182 may be disposed between the rear cover 170 and the second support spring 186.

The sleeve 182 may have a cylindrical shape of which the inside is empty. The sleeve 182 has a predetermined thickness and connects the rear cover 170 to the spring coupling part 186 b. That is, the sleeve 182 may be disposed at a point corresponding between the coupling hole 172 and the spring coupling hole 186 c to allow the sleeve 182 to absorb coupling force of the first coupling member S1.

Due to this configuration, a separate coupling member for coupling the second support spring 186 to the rear cover 170 may not be required, and thus, the coupling hole to which th coupling member is coupled may be omitted in the rear cover 170. Also, the rear cover 170 may be simplified in structure, and the number of coupling members coupled to the rear cover 170 may be reduced to reduce the number of times of coupling of the coupling member.

Also, while the coupling member S1 is coupled, the sleeve 182 absorbs the coupling force of the coupling member to prevent the rear cover 170 from being deformed.

FIG. 14 is a rear perspective view illustrating a portion of a main body of a compressor according to a third embodiment, FIG. 15 is a rear perspective view of a stator cover according to the third embodiment, FIG. 16 is a perspective view of a resonant spring according to the third embodiment, and FIG. 17 is a perspective view of the resonant spring of FIG. 16 when viewed in a different direction.

This embodiment has a feature in which a new spring structure is applied to the linear compressor.

Referring to FIG. 14, a compressor according to a third embodiment includes a motor assembly 140 providing driving force to a piston 130, a stator cover 300 coupled to the motor assembly 140, a spring assembly 400 coupled to the stator cover 300, and a second support device 185 coupled to the spring assembly 400.

In detail, the stator cover 30 includes a body 310 having an opening 311 through which the piston 130 passes and one or more rear cover coupling parts 320 extending backward from the body 310.

The body 310 may include a front surface 310 a coupled to a frame 110 and a rear surface 310 b defining a surface that is opposite to the front surface 310 a. The front surface 310 a and/or the rear surface 310 b may have a plane perpendicular to an axial direction.

For example, the body 310 may have a disk shape. Also, an opening 311 may be defined in a central portion of the body 310, and the piston 130 and a magnet 138 may pass through the opening 311.

Also, the body 310 includes a coupling hole 312 through which a coupling member (not shown) passes.

The coupling hole 312 extends from a front surface 310 a to a rear surface 310 b of the body 310. Also, the coupling hole 312 may be provided in plurality. The plurality of coupling holes 312 may be disposed to be spaced apart from each other in the front surface 310 a in a circumferential direction. Each of the plurality of coupling members may pass through the coupling hole 312 and then be coupled to the frame 110.

Each of the rear cover coupling parts 320 lengthily extends backward from a rear surface 310 b of the body 310 so as to be coupled to a rear cover 460 that will be described later. Here, the rear cover coupling part 320 may have a cross-sectional area that gradually decreases backward from the rear surface 310 b of the body 310. That is, a front surface of the rear cover coupling part 320 may have an area less than that of a rear surface 320 b thereof.

Also, a coupling hole 321 to which a coupling member is coupled may be defined in each of the rear cover coupling parts 320.

The coupling groove 321 may be defined in a rear surface 320 b corresponding to an end of the rear cover coupling part 320. That is, the coupling groove 321 may be recessed by a predetermined depth forward from the rear surface 320 b of the rear cover coupling part 320. Thus, the coupling member may be coupled to the coupling groove after passing through a rear cover 460 that will be described later.

The plurality of rear cover coupling parts 320 may be disposed to be spaced apart from each other in the circumferential direction of the body 310. Here, for example, the plurality of rear cover coupling parts 320 may be provided in three. The three rear cover coupling parts 320 may be disposed to be spaced the same interval from each other in the circumferential direction.

Particularly, the plurality of rear cover coupling parts 320 are disposed to be spaced part from the body 310 along an edge of the opening 311 in the circumferential direction. This is done for a reason in which springs 40, 420, and 430 that will be described later are disposed to surround the outside of the plurality of rear cover coupling parts 320. That is, the plurality of rear cover coupling parts 320 is disposed to be more adjacent to the inside, i.e., the opening 311 than the outside from the rear surface of the body.

The spring assembly 400 is provided in a coil spring shape that is stretched and compressed in the axial direction. The spring assembly 400 is provided in a shape extending spirally in the axial direction. Here, the spring assembly 400 may extend spirally with respect to a central axis C of the spring.

A central axis of the linear compressor according to this embodiment and the central axis C of the spring may match each other. Particularly, the central axis C of the spring may match a central axis of reciprocating movement of the motor assembly 140.

Also, a suction muffler (not shown) is disposed inside the spring assembly 400. The spring assembly 400 extend in the axial direction to surround the suction muffler.

The spring assembly 400 may be divided into a spring body 402 and both end portions of the spring body 402. For convenience of description, the end portion disposed at the front in the axial direction of the spring body 402 is called a front spring link 404, and the end portion disposed at the rear in the axial direction of the spring body 402 is called a rear spring link 406.

In detail, the spring assembly 400 includes a support 440 coupled to the front spring link 404 and a rear cover 460 coupled to the rear spring link 406. The support 440 and the rear cover 460 are understood as constituents for fixing the spring assembly 400 to the stator cover 300.

The support 440 may be provided in a flat plate shape that extends in the radial direction. Thus, the support 440 may provide one plane that is perpendicular to the axial direction. Also, the support 440 may have a portion protruding backward in the axial direction to fix the front spring link 404.

Although not shown, the support 440 may be coupled to the piston 130. Particularly, the support 440 may be coupled to a portion that extending outward in the radial direction from the rear side of the piston 130. That is, the support 440 may be coupled to a rear end of the piston 130.

Thus, the support 440 may be provided as a flat plate having a ring shape corresponding to the rear end of the piston 130. Also, an opening 441 a through which the suction muffler (not shown) passes may be defined in the support 440.

The support 440 includes a support body 441 coupled to the piston 130 and a first spring coupling part 442 extending outward from a circumference of the support body 441 in the radial direction.

The support body 441 may have a disk shape in which an opening 441 a is defined. Also, one or more piston coupling parts 441 b coupled to the piston 130 may be disposed on the support body 441 so as to be spaced apart from each other in the circumferential direction.

The first spring coupling part 442 is understood as a portion to which the front spring link 404 is coupled. For example, the first spring coupling part 442 may extend outside from an outer circumferential surface of the support body 441 in the radial direction.

The first spring coupling part 442 may be provided in plurality. The plurality of first spring coupling parts 442 may be disposed to be spaced apart from each other along a circumference of the support body 441. The first spring coupling part 442 may be provided to fix an end of the front spring link 404.

For example, the first spring coupling part 442 may have an inner space into which the end of the front spring link 404 is inserted.

The rear cover 460 may be provided in a flat plate shape that extends in the radial direction. The rear cover 460 may be disposed to face the support 440. Thus, the rear cover 460 may provide one plane that is perpendicular to the axial direction. Also, the rear cover 460 may have a portion protruding forward in the axial direction to fix the rear spring link 406.

The rear cover 460 may be coupled to the stator cover 300. Particularly, the rear cover 460 be coupled to the rear cover coupling part 320 of the stator cover 300 by a coupling member 320.

In detail, the rear cover 460 includes a rear cover body 461 and a second spring coupling part 462 extending outward from a circumference of the rear cover body 461 in the radial direction.

The rear cover body 461 may be provided in a flat plate shape having a predetermined area. Also, an insertion hole 461 a into which the second spring support part 187 is inserted may be defined in a central portion of the rear cover body 461.

The second spring coupling part 462 is understood as a portion to which the rear spring link 406 is coupled. For example, the second spring coupling part 462 may extend from an outer circumferential surface of the rear cover body 461 in the radial direction.

The second spring coupling part 462 may be provided in plurality. The plurality of second spring coupling parts 462 may be disposed to be spaced apart from each other along a circumference of the rear cover body 461. The second spring coupling part 462 may be provided to fix an end of the rear spring link 406.

For example, the second spring coupling part 462 may have an inner space into which the end of the rear spring link 406 is inserted.

Also, the rear cover 460 further includes one or more coupling parts 463 that are coupled to the rear cover coupling part 320 by using the coupling member.

The coupling part 463 extends outward from the circumference of the rear cover body 461 in the radial direction. Here, one or more coupling hole 463 a may be defined in the coupling part 463, and thus, the coupling member may be coupled to the rear cover coupling part 320 after passing through the coupling hole 463 a.

Also, the coupling part 463 may be provided in plurality. The plurality of coupling parts 463 may be disposed to be spaced apart from each other along a circumference of the rear cover body 461. Here, the number of coupling parts 463 may correspond to that of rear cover coupling parts 320.

Also, the plurality of coupling parts 463 and the plurality of second spring coupling parts 462 may be alternately disposed with respect to each other.

The second support device 185 includes a second spring support part 187 mounted on the rear cover 460 and a second support spring 186 inserted into the second spring support part 187.

The second support spring 186 has a circular plate spring shape. Also, a spring coupling hole 188 coupled to the rear cover coupling part 320 through the coupling member may be defined in the second support spring 186.

The spring coupling hole 188 is defined in a point corresponding to the coupling hole 463 a defined in the rear cover 460. Also, the spring coupling hole 188 may be provided in plurality and disposed to be spaced apart from each other in the circumferential direction.

Thus, the second support spring 186, the rear cover 460, and the rear cover coupling part 320 may be coupled to each other at one time by the single coupling member.

The spring assembly 400 further includes a plurality spring strands 410, 420, and 430, Each of the plurality of spring strands 410, 420, and 430 spirally rotates with respect to a central axis C of the spring.

The plurality of spring strands 410, 420, and 430 may have the same shape and be spaced the same interval from each other in the circumferential direction so as to be coupled to each other. Also, the plurality of spring strands 410, 420, and 430 include a first spring strand 410, a second spring strand 420, and a third spring strand 430.

The first, second, and third spring strands 410, 420, and 430 are disposed to differently rotate in the circumferential direction. Here, the circumferential direction means one of a clockwise direction and a counterclockwise direction. Also, the first, second, and third spring strands 410, 420, and 430 are disposed to differently rotate in the circumferential direction. That is, each of the spring strands 410, 420, and 430 may be disposed to rotate at an angle of about 120 degrees.

Also, each of the spring strands 410, 420, and 430 may be divided into a spring body and both end portions (a front spring link and a rear spring link).

In detail, the first spring strand 410 is divided into a first spring body 412, a first front spring link 414, and a first rear spring link 416. The second spring strand 420 is divided into a second spring body 422, a second front spring link 424, and a second rear spring link 426. The third spring strand 430 is divided into a third spring body 432, a third front spring link 434, and a third rear spring link 436.

Each of the first, second, and third spring strands 410, 420, and 430 forms a virtual circle having a spring diameter R in a radial direction to extend in an axial direction. Here, a center of the spring diameter R is referred to as a spring center, and an extension line of the spring center in the axial direction is referred to as a spring central axis C. The spring central axis C may match a central axis of reciprocating movement of the motor assembly 140 including the piston 130.

The first, second, and third spring strands 410, 420, and 430 extend with the same spring diameter R in the axial direction. Thus, the spring body 402 may have a cylindrical shape as a whole.

Each of the first, second, and third front spring links 414, 424, and 434 is bent inward in the radial direction. In other words, the first, second, and third front spring links 414, 424, and 434 are disposed inside the spring body 402 in the radial direction. Also, the first, second, and third front spring links 414, 424, and 434 may be understood as extending toward the central axis C.

The support 440 is coupled to the first, second, and third front spring links 414, 424, and 434. That is, the support 440 may be understood as a constituent that fixes the plurality of front spring links 414, 424, and 434 to the same plane in the axial direction.

Each of the first, second, and third rear spring links 416, 426, and 436 is bent inward in the radial direction. In other words, the first, second, and third rear spring links 416, 426, and 436 are disposed inside the spring body 402 in the radial direction. Also, the first, second, and third rear spring links 416, 426, and 436 may be understood as extending toward the central axis C.

The rear cover 460 is coupled to the first, second, and third rear spring links 416, 426, and 436. That is, the rear cover 460 may be understood as a constituent that fixes the plurality of rear spring links 416, 426, and 436 to the same plane in the axial direction.

The linear compressor including the above-described constituents according to the embodiment may have the following effects.

First, since a structure in which an end of the stator cover and an end of the resonant spring are supported together on the same plane in the axial direction is provided, the rear cover may be simplified in shape to improve strength of the rear cover.

In addition, since the rear cover has a single disk shape, the shell may be reduced in size to miniaturize the linear compressor.

Second, the stator cover, the rear cover, and the plate spring may be coupled to each other at one time to simplify a structure of the rear cover and significantly reduce an assembling time. That is, it may be unnecessary to provide a separate coupling member for fixing the plate spring to the rear surface of the rear cover.

Third, the plurality of rear cover coupling parts may be disposed to be spaced apart from each other in the circumferential direction of the body of the stator cover, and the single resonant spring may be disposed to surround the outside of the plurality of rear cover coupling parts.

Here, the front spring link having the plurality of spring strands may be fixed to the support connected to the rear end of the piston, and the rear spring link having the plurality of spring strands may be fixed to the rear cover. Thus, since both the ends of the spring are fixed to be used for all of the stretching and the compressing force of the spring, the spring may support the larger load or the repeated load.

Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art. 

What is claimed is:
 1. A linear compressor comprising: a shell; a cylinder that is disposed in the shell and that extends in an axial direction, the cylinder defining a compression space therein configured to receive refrigerant; a frame coupled to an outside of the cylinder; a piston disposed in the cylinder and configured to reciprocate in the axial direction of the cylinder; a stator cover coupled to the frame; a rear cover coupled to the stator cover; and springs disposed between the stator cover and the rear cover, wherein the stator cover comprises a stator cover body, and a plurality of rear cover coupling parts that extend from the stator cover body toward the rear cover and are coupled to the rear cover, and wherein an end of the plurality of rear cover coupling parts and an end of the springs are disposed on a plane that is defined by the rear cover and that is orthogonal to the axial direction.
 2. The linear compressor according to claim 1, wherein the stator cover body defines an opening through which the piston passes, and wherein the plurality of rear cover coupling parts are spaced apart from one another along a circumferential direction of the stator cover body.
 3. The linear compressor according to claim 2, wherein the rear cover defines a plurality of coupling holes configured to couple to the plurality of rear cover coupling parts of the stator cover, respectively.
 4. The linear compressor according to claim 3, wherein the rear cover comprises a plurality of spring coupling protrusions that protrude toward the stator cover and that are configured to couple to one or more of the springs.
 5. The linear compressor according to claim 4, wherein the plurality of coupling holes and the plurality of spring coupling protrusions are spaced apart from each other along a circumferential direction of the rear cover.
 6. The linear compressor according to claim 5, wherein the plurality of coupling holes and the plurality of spring coupling protrusions are alternately disposed along the circumferential direction of the rear cover, and wherein one or more of the plurality of spring coupling protrusions are disposed between two of the plurality of coupling holes along the circumferential direction of the rear cover.
 7. The linear compressor according to claim 3, wherein the rear cover has a first surface configured to support one or more of the springs, and a second surface opposite to the first surface, and wherein the linear compressor further comprises a support device disposed at the second surface of the rear cover and configured to support the rear cover in the shell.
 8. The linear compressor according to claim 7, wherein the support device comprises: a spring support part inserted into the second surface of the rear cover; and a plate spring coupled to the spring support part, at least a portion of the plate spring being inserted into the spring support part.
 9. The linear compressor according to claim 8, wherein the plate spring comprises: a spring body inserted into the spring support part; and a plurality of spring coupling parts that extend from a circumference of the spring body to positions facing the plurality of coupling holes.
 10. The linear compressor according to claim 9, wherein each of the plurality of spring coupling parts defines a spring coupling hole at the position facing one of the plurality of coupling holes.
 11. The linear compressor according to claim 9, further comprising a plurality of sleeves, each sleeve being disposed between the rear cover and one of the plurality of spring coupling parts.
 12. The linear compressor according to claim 10, further comprising a plurality of coupling members, each coupling member passing through the spring coupling hole and the corresponding coupling hole to be coupled to one of the plurality of rear cover coupling parts.
 13. The linear compressor according to claim 2, further comprising a spring support configured to support one or more of the springs, wherein the spring support is connected to a rear end of the piston and disposed between the stator cover and the rear cover.
 14. The linear compressor according to claim 13, wherein the springs comprise: a plurality of first springs disposed between the spring support and the stator cover; and a plurality of second springs disposed between the spring support and the rear cover, wherein an end of each of the plurality of second springs and an end of each of the plurality of rear cover coupling parts are disposed on a same plane orthogonal to the axial direction.
 15. The linear compressor according to claim 14, wherein the plurality of first springs are spaced apart from one another along the circumferential direction of the stator cover body, and wherein the plurality of second springs are spaced apart from one another in a circumferential direction of the rear cover.
 16. The linear compressor according to claim 3, wherein the plurality of rear cover coupling parts are spaced apart from one another along a circumference of the opening of the stator cover body, and wherein each of the springs surrounds an outside of one of the plurality of rear cover coupling parts.
 17. The linear compressor according to claim 16, wherein each of the springs comprises a plurality of spring strands, wherein each of the plurality of spring strands comprises: a spring body that extends in a spiral direction about a spring central axis that extends in the axial direction; a front spring link that extends from a first side of the spring body and that defines a first end of the spring body; and a rear spring link that extends from a second side of the spring body and that defines a second end of the spring body.
 18. The linear compressor according to claim 17, further comprising a spring support connected to a rear end of the piston, wherein the front spring link of each of the plurality of spring strands is fixed to the spring support.
 19. A linear compressor comprising: a shell; a cylinder that is disposed in the shell and that extends in an axial direction, the cylinder defining a compression space therein configured to receive refrigerant; a frame coupled to an outside of the cylinder; a piston disposed in the cylinder and configured to reciprocate in the axial direction of the cylinder; a stator cover coupled to the frame; a rear cover coupled to the stator cover, the rear cover comprising a front surface facing the stator cover; and springs disposed between the stator cover and the rear cover, wherein the stator cover comprises a stator cover body and a plurality of rear cover coupling parts that extend from the stator cover body toward the rear cover and that are coupled to the rear cover, and wherein an end of each of the plurality of rear cover coupling parts and an end of each of the springs are attached to the front surface of the rear cover.
 20. A linear compressor comprising: a shell; a cylinder that is disposed in the shell and that extends in an axial direction, the cylinder defining a compression space therein configured to receive refrigerant; a piston disposed in the cylinder and configured to reciprocate in the axial direction of the cylinder; a stator that surrounds at least a portion of an outside of the cylinder; a stator cover that faces a rear end portion of the stator, the stator cover comprising a stator cover body that surrounds the outside of the cylinder, and a plurality of coupling parts that extend from the stator cover body toward a rear side of the shell; a rear cover disposed rearward of the stator cover body toward the rear side of the shell, the rear cover having a first surface coupled to rear ends of the plurality of coupling parts of the stator cover and a second surface that faces the rear side of the shell; and at least one spring that extends between the stator cover body and the first surface of the rear cover and that contacts the stator cover body and the first surface of the rear cover. 